Ivy League style was born in the elite universities of America's East Coast, and went on to conquer the world. A new book, Hollywood and the Ivy Look, celebrates the years when movie stars exhibited a firm grip on a style of dressing that continues to exert great influence on what men wear.

The appeal of the real Ivy look, which bears little relation to the brightly coloured clothes that have come to be referred to as preppy (another reference to elite American educational institutions), is that it's beautifully low-key. Crudely put, this is about stealth wealth, not luxury or razor-sharp style, which is why shirts are often in Oxford cloth, sports jackets are often in tweed, suits are undarted and have soft shoulders, and lapels and ties are narrow. It's restrained and smart but also - crucially - comfortable. It speaks of the confidence (and uniformity) of the class that first adopted it.

In the 50 years since Ivy's heyday - President John F Kennedy's period in office was arguably the zenith of the era - the style has persisted. These incredible photographs, which between them offer a variety of convincing definitions of the phrase "smart casual", demonstrate why.

Hollywood And The Ivy Look, by Tony Nourmand and Graham Marsh, is out now £45, Reel Art Press)